Plastic floor-wall transition methods, materials, and apparatus

ABSTRACT

A method of flooring installation includes positioning a welding tip having a v-shaped plastic welding rod therein adjacent to a v-shaped joint formed between plastic flooring and plastic trim and heating the flooring, trim, and welding rod to flow the welding rod into the v-shaped joint to form a plastic weld bead and seal the joint. A welding tip and a welding rod are also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/285,804 filed Dec. 11, 2009. The disclosure of the above applicationis incorporated herein by reference.

TECHNICAL FIELD

The present invention generally relates to flooring and, moreparticularly, to methods of covering floors and floor-wall transitionswith plastic material, and to related materials and apparatus.

BACKGROUND

Plastic flooring is generally known in the art, and may be installedaccording to the following steps for a basic floor. First, referringgenerally to prior art FIG. 5, flat sheets 110 of plastic floor are laidout over the entirety of a sub-floor 112 to be covered, and must betightly dry fit to one another to ensure tight seams between adjacentsheets 110. Second, floor-wall moldings 114 composed of the flooringmaterial are dry fit at all floor-wall transitions. More specifically,wall portions 116 of the moldings 114 are held against correspondingbases 118 of walls 120, and floor portions 122 of the moldings 114 areoverlapped against corresponding margins (not shown) of the floor sheets110. Third, the floor sheets 110 are scribed along edges of the floorportions 122 of the moldings 114 to define cut lines on the floor sheets110. Fourth, the moldings 114 are removed and the floor sheets 110 arecut along the scribed cut lines and the excess floor margins are removedand discarded. Fifth, the moldings 114 are dry fit to the freshly cutfloor sheets 110 to ensure tight seams between adjacent moldings 114 andthe floor sheets 110. Sixth, the floor sheets 110 are removed. Seventh,an adhesive 124 is applied to the sub-floor 112. Eighth, all floorsheets 110 are wet fit and rolled in place over the adhesive 124. Ninth,an additional adhesive 126 is applied to the subfloor 112 and wall bases118. Tenth, the moldings 114 are wet fit over the adhesive 126.Eleventh, the seams 128 between the floor sheets 110 and the moldings114 are filled with welding beads 130 by heat welding of rods of thefloor material to the sheets 110 and moldings 114.

Currently, high speed welding tips can be used on heat guns for thepurpose of accomplishing relatively high speed welding between plasticmaterials. Typically, such high speed plastic welding tips incorporatean attachment portion that is generally cylindrical for attachment to aheat gun. The attachment portion tapers from its generally cylindricalarea to a generally oval output at the opposite end. The output end isused to direct the flow of hot air used in the welding process. Awelding rod feed section is secured to the output end. Typically, thewelding rod feed section is cylindrical having a generally circularcross-section for receiving a plastic welding rod.

While the aforementioned floor covering method and apparatus aregenerally effective, certain limitations are inherent. For example, thefloor-transition moldings can be somewhat costly and the moldingtechniques are particularly time-consuming. Also, current welding tipsand rod shapes may limit the strength of welds between flooring sheetsand moldings.

SUMMARY

A method of flooring installation includes applying plastic flooring toa sub-floor, applying plastic trim to a base portion of a wall to form av-shaped joint between the flooring and the trim, positioning a weldingtip having a v-shaped plastic welding rod therein adjacent to the joint,and heating the flooring, trim, and welding rod to flow the welding rodinto the v-shaped joint to form a plastic weld bead and seal the joint.This method may reduce plastic flooring installation time as well asmaterial and labor costs when compared to conventional plastic flooringinstallation techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a plan view of an exemplary embodiment of a welding tip;

FIG. 2 is an end view of the welding tip of FIG. 1;

FIG. 2A is a fragmentary end view of a welding tip according to anotherembodiment;

FIG. 3 is a fragmentary cross-sectional view of an exemplary embodimentof a floor-wall transition produced in accordance with an exemplaryembodiment of a flooring method;

FIG. 4 is a cross-sectional view of an exemplary embodiment of a weldingrod; and

FIG. 5 is a fragmentary cross-sectional view of a prior art floor-walltransition produced in accordance with a flooring method of the priorart.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a plan view of a welding tip 10 adapted to be received on aheat gun (not shown). Heat guns are well-known. Suitable heat guns foruse in connection with the welding tip 10 include, but are not limitedto, heat guns made by LEISTER®, FORSTHOFF®, and SINCLAIR®. It will beappreciated that any suitable heat gun may be used in accordance withthe present invention.

The welding tip 10 has a base generally indicated at 12. The base 12includes a generally cylindrical attachment portion 14 that is adaptedto engage the heat gun (not shown). The attachment portion 14 mayinclude one or more longitudinal slots 16. The longitudinal slots 16give the attachment portion 14 some flexibility in order to firmlyengage the heat gun. The base 12 extends from the attachment portion 14to an output end 18. The output end 18 directs the flow of hot air, aswill be described more fully below. The output end 18 may have anopening 20, which may be partially oval-shaped and partially straight asshown.

The welding tip 10 further includes a welding rod feed section 22. Thewelding rod feed section 22 is generally tubular and is secured to theoutput end 18 of the base 12. In one embodiment, the welding rod feedsection 22 may have a flattened half-oval shaped cross-section with acorresponding opening 24, as best seen in FIG. 2. It will be appreciatedthat the rod feed section 22 may have any suitable cross-sectionalshape.

The welding tip 10 further includes a lip generally indicated at 26. Thelip 26 includes a securing portion 28 for securing the lip 26 with onewall 25 of the welding rod feed section 22. The securing portion 28 mayextend beyond the edge of the welding rod feed section 22, as best seenin FIG. 1. The lip 26 further includes a flange 30 extending from thesecuring portion 28 at an angle relative to one wall 25 of welding rodfeed section 22. In one preferred embodiment, the flange 30 extends atan angle of about 20-30°, for instance 25°, relative to the plane of thewall 25. The flange 30, as best shown in FIG. 1, may be spoon-shaped ordish-shaped and have a convex surface facing the opening 24 in thewelding rod feed section 22. The convex surface may comprise metal thatmay be highly polished. Also, as best shown in FIG. 2, the flange 30 mayhave radiused lower corners.

The welding tip 10 may be composed of metal, for example, 304 stainlesssteel tubing, or any other suitable material. The base 12, feed section22, and lip 26 may be secured to one another by welding, fastening, orany other suitable connection.

FIG. 2A illustrates another embodiment of a welding tip 10 including abase 112, a weld rod feed section 122 and corresponding opening 124, anda flange 130. In this embodiment, the feed section 122 and/or opening124 has a v-shaped cross-section corresponding to the cross-sectionshown in FIG. 4. The v-shaped cross section need not be identical to thecross-section shown in FIG. 4 and, for example, may be larger toaccommodate a slip fit of material therethough.

FIG. 3 is a fragmentary cross-sectional view of an exemplary embodimentof a floor-wall transition T produced in accordance with one embodimentof a method of floor covering disclosed herein below. As shown in FIG.3, plastic flooring 40 is positioned against and adhered to a sub-floorF with an adhesive 42, and plastic trim 44 is positioned against andadhered to a wall W with an adhesive 46. A v-shaped joint is establishedbetween the flooring 40 and the trim 44. Also, a plastic weld bead 48 isheat welded in the v-shaped joint to corresponding portions of theflooring 40 and trim 44. The flooring 40 may include one or moreindividual sheets, rolled sheets, tiles, interlocking tiles, or anyother suitable flooring product. The trim 40 may include one or morebase moldings, cove bases, or the like, and may be in the form ofstrips, segments, inside corner pieces, outside corner pieces, or thelike. The flooring 40 and the trim 44 may have the same thickness,although this is not required. The adhesives 42 and/or 46 may include PA127, PA 139, and/or Eclectic 6100, all of which are available fromOscoda Plastics, the Assignee of the present invention, of Oscoda, Mich.

The flooring 40 and trim 44 and the weld bead 48 are preferably madefrom the same plastic material, for example, a thermoplastic material.The plastic material may comprise a vinyl material, and preferably maycomprise polyvinylchloride. The plastic material may further include asuitable fiber reinforcement. One suitable plastic material is soldunder the name PROTECT-ALL® by Oscoda Plastics, the Assignee of thepresent invention. It will be appreciated that while the preferredmaterial is polyvinylchloride, any suitable plastic material may be usedwithin the context of the present invention.

The subfloor F may comprise any material. By way of non-limitingexample, the subfloor F may comprise wood, such as plywood or orientedstrand board. Similarly, the subfloor F may comprise concrete. Whilewood and concrete are specifically discussed as being suitable subfloorF, it will be appreciated that any suitable subfloor F may be usedwithin the context of the present invention.

FIG. 4 is a cross-sectional view of one embodiment of a welding rodgenerally indicated at 60 that may be used to produce the weld bead 48of FIG. 3. As shown in FIG. 4, the welding rod 60 has a generallytriangular profile. The welding rod 60 can be of any desired length. Inone embodiment, the cross-sectional shape of the welding rod 60 isconstant along the entire length. In one embodiment, the triangularprofile may comprise a substantially right triangle with the oppositeangles each being about 43-45°. The welding rod 60 may include anintersection 62 defined by the right angle. The welding rod 60 mayfurther include side walls 64 extending from the intersection 62. Byusing a welding rod 60 having the side walls 64 extending atsubstantially 86-90° from one another, a more uniform weld may beachieved. This is because the floor-wall transition T of FIG. 3 issimilarly configured. The side walls 64 may be generally planar. Thewelding rod 60 further includes a long wall or hypotenuse generallyindicated at 66. The hypotenuse 66 has generally planar and opposed endportions 68 at the outer edges adjacent the side walls 64 thereof. Inone embodiment, the hypotenuse 66 may further include an incurvateportion 70 intermediate the generally planar end portions 68. Theincurvate portion 70 provides a generally concave surface recessed inand along the welding rod 60. The incurvate portion 70 may be radiused,faceted, or the like.

It is preferred that the welding rod 60 be made from a similar materialto that of the flooring 40 and trim 44. In one embodiment, the weldingrod 60 may comprise polyvinylchloride. Further, by utilizing a weldingrod 60 having a generally triangular configuration as described, aharder welding rod may be available than ones able to be used in priorapplications. By way of non-limiting example, the welding rod maycomprise PVC (polyvinylchloride) having a durometer hardness of 90 ShoreA.

In accordance with the various embodiments, an exemplary methodgenerally involves applying plastic flooring on a sub-floor, applyingplastic trim to a base portion of a wall to form a v-shaped jointbetween the flooring and the trim, and welding the joint by positioninga welding tip having a v-shaped welding rod therein adjacent the jointand heating the flooring, trim, and welding rod to allow the welding rodto flow into the v-shaped joint. Portions of the method may be describedin reference to FIGS. 1-4. The method steps may or may not besequentially processed, and the invention encompasses any sequencing,overlap, or parallel processing of such steps.

First, an adhesive may be applied to a sub-floor. For example, theadhesive may be troweled on, or applied in any other suitable manner. Ofcourse, suitable sub-floor preparation may be carried out before theadhesive is applied. For example, a sub-floor may be leveled, sanded,cleaned, or prepared in any other suitable manner to receive a floorcovering according to the manufacturer's guidelines.

Second, plastic flooring may be applied to a sub-floor. For example, theflooring may include individual sheets, rolled sheet, tiles,interlocking tiles, or the like. The flooring may be arranged on theadhesive so that outer edges of the flooring are tight to the walls andfixed objects. The flooring may be applied so that adjacent edges formseams suitable for heat welding with a heat gun, tip, and welding rod.

Third, an adhesive may be applied to a wall. For example, the adhesivemay be troweled on, caulked on, applied in any other suitable manner tobase portions of walls. For example, base portions of walls may be from0″ to 9″ from an adjacent floor, but any suitable size and scope of wallbase portions may be applied with adhesive.

Fourth, plastic trim may be applied to a wall. For example, the trim maybe applied to a base portion of the wall and may include strips,segments, inside corner pieces, outside corner pieces, or the like. Thetrim may be arranged on the adhesive so that lower edges of the trim aretight to the flooring. The trim may be applied so that its lower edgesand the flooring form seams suitable for heat welding with a heat gun,tip, and welding rod.

Fifth, a plastic weld bead may be formed at a joint between plastic trimon a wall and flooring on a subfloor. For example, a heat gun and awelding tip may be used to apply a welding rod to the joint to fill thejoint.

According to one specific example of this step, and with reference toFIGS. 1 and 2, the welding tip 10 may be positioned on a heat gun suchthat the attachment portion 14 is positioned about a nozzle of the gun.The welding tip 10 is oriented so that the welding rod feed section 22is situated above the base 12 relative to the joint between the flooring42 and the trim 44 (i.e., rotate FIG. 1 180° counterclockwise to weldfrom left to right in FIG. 1). The welding rod 60 is positioned in theopening 24 in the welding rod feed portion 22 of the welding tip 10. Theheat gun, having the welding tip 10 thereon, may be heated to anysuitable welding temperature. By way of non-limiting example, betweenabout 500° F. and 800° F. The settings for individual heat guns mayvary. It is preferred, however, that in one embodiment the heat gun beset to achieve the above specified temperature. Upon heating of the heatgun, the welding rod 60 is positioned in the welding rod feed section22, and the tip 10 is positioned over the joint between the flooring 40and the trim 44 such that the intersection 62 of the welding rod 60 ispositioned in and along the joint. The welding tip 10 provides hot airdirected through the opening 20 and underneath the emerging welding rod60 towards the flooring 40 and trim 44. It is desirable that the weldingtip 10 provide heat to both the flooring 40 and the trim 44 and the rod60 to properly weld the flooring 40 and the trim 44 together. In oneembodiment, the flooring 40 and the trim 44 may be welded together at arate of one to two linear feet per minute.

The heat gun is held in a position such that the flange 30 of thewelding tip 10 is at about a 43-45 degree angle. The convex surface ofthe flange 30 applies an inward pressure to the heated welding rod, morespecifically the incurvature portion 70, to press and dimensionallycontour the solidifying welding rod into the joint between the flooring40 and the trim 44 during the welding process. The highly polishednature of the convex surface may provide the finished weld bead with asmooth surface profile. Further, the highly polished surface may reducethe amount of material that may otherwise adhere to the convex surface.Once the joint has been welded, the tip 10 may be removed from theflooring 40 and the trim 44.

Accordingly, the method described above involves less than half thesteps of the prior art process described in the background section. Onthe whole, it is believed that the present disclosure may reduce plasticflooring installation time for typical applications by several days,reduce product costs by about 30%, decrease manufacturing lead time byabout 50%, and decrease the labor portion by about 30%.

The foregoing description is considered illustrative only. Theterminology that is used is intended to be in the nature of words ofdescription rather than of limitation. Many modifications and variationswill readily occur to those skilled in the art in view of thedescription. Thus, the foregoing description is not intended to limitthe invention to the embodiments described above. Accordingly the scopeof the invention as defined by the appended claims.

What is claimed is:
 1. A welding tip for welding plastic material, thewelding tip comprising: a base that includes an attachment portion andan output end, the attachment portion being adapted to engage a heat gunand the output end being configured to direct a flow of hot air; awelding rod feed section secured to the base and having an opening thatguides a plastic welding rod through the opening so that the plasticwelding rod intersects the flow of hot air when the heat gun is heated,the welding rod feed section having a generally triangularly-shapedcross-section throughout its extent, and the opening having a v-shapedcross section; and a flange secured to the welding rod feed section andextending at an angle relative to the welding rod feed section, theflange having a convex surface facing the opening in the welding rodfeed section and configured to apply pressure to the plastic welding rodas the plastic welding rod is heated and positioned in and along a jointbetween surfaces to be welded, the plastic welding rod having agenerally triangular cross-sectional profile that is complementary tothe generally triangularly-shaped cross-section of the welding rod feedsection, wherein the generally triangular cross-sectional profile of theplastic welding rod includes an intersection from which a first and asecond side wall extend to a hypotenuse wall opposite the intersection,the hypotenuse wall having opposed first and second generally planar endportions adjacent the first and second side walls and having anincurvature portion between the first and second end portions, andwherein the incurvature portion presents a concave surface thatgenerally complements the flange's convex surface in order to facilitatea pressing action between the surfaces during a welding event.
 2. Thewelding tip of claim 1, wherein the first and second side walls extendfrom the intersection at an angle of about 86-90°, and wherein the firstand second side walls form opposed first and second angles with thehypotenuse wall each between about 43-45°.
 3. The welding tip of claim1, wherein the convex surface of the flange that applies pressure to thewelding rod is polished.
 4. The welding tip of claim 1, wherein theoutput end includes an air opening to direct the flow of hot air.
 5. Thewelding tip of claim 1, wherein the flange extends at an angle of 20° to30° relative to the welding rod feed section.
 6. The welding tip ofclaim 1, wherein the plastic welding rod is composed of polyvinylechloride.